gdb/linux-nat.c:
- Workaround RHEL-5 kernels for detaching SIGSTOPped processes (BZ 498595).

Index: gdb-7.2.50.20110328/gdb/elfread.c
===================================================================
--- gdb-7.2.50.20110328.orig/gdb/elfread.c	2011-03-28 18:46:16.000000000 +0200
+++ gdb-7.2.50.20110328/gdb/elfread.c	2011-03-28 18:48:19.000000000 +0200
@@ -1083,7 +1083,7 @@ elf_gnu_ifunc_resolver_return_stop (stru
 #define BUILD_ID_VERBOSE_NONE 0
 #define BUILD_ID_VERBOSE_FILENAMES 1
 #define BUILD_ID_VERBOSE_BINARY_PARSE 2
-static int build_id_verbose = BUILD_ID_VERBOSE_FILENAMES;
+static int build_id_verbose = BUILD_ID_VERBOSE_NONE;
 static void
 show_build_id_verbose (struct ui_file *file, int from_tty,
 		       struct cmd_list_element *c, const char *value)
@@ -2173,8 +2173,10 @@ find_separate_debug_file_by_buildid (str
       if (build_id_name != NULL
 	  && filename_cmp (build_id_name, objfile->name) == 0)
         {
+#if 0 /* RHEL-5 backward behavior compatibility.  */
 	  warning (_("\"%s\": separate debug info file has no debug info"),
 		   build_id_name);
+#endif
 	  xfree (build_id_name);
 	}
       else if (build_id_name != NULL)
Index: gdb-7.2.50.20110328/gdb/corelow.c
===================================================================
--- gdb-7.2.50.20110328.orig/gdb/corelow.c	2011-03-28 18:46:16.000000000 +0200
+++ gdb-7.2.50.20110328/gdb/corelow.c	2011-03-28 18:47:56.000000000 +0200
@@ -282,7 +282,7 @@ add_to_thread_list (bfd *abfd, asection 
     inferior_ptid = ptid;			/* Yes, make it current.  */
 }
 
-static int build_id_core_loads = 1;
+static int build_id_core_loads = 0;
 
 static void
 build_id_locate_exec (int from_tty)
Index: gdb-7.2.50.20110328/gdb/linux-nat.c
===================================================================
--- gdb-7.2.50.20110328.orig/gdb/linux-nat.c	2011-03-28 18:46:16.000000000 +0200
+++ gdb-7.2.50.20110328/gdb/linux-nat.c	2011-03-28 18:47:56.000000000 +0200
@@ -1774,8 +1774,22 @@ get_pending_status (struct lwp_info *lp,
 			    target_signal_to_string (signo));
     }
 
-  if (*status == 0 && GET_PID (lp->ptid) == pid_was_stopped)
-    *status = W_STOPCODE (SIGSTOP);
+  /* Workaround RHEL-5 kernel which has unreliable PTRACE_DETACH, SIGSTOP (that
+     many TIDs are left unstopped).  See RH Bug 496732.  */
+  if (GET_PID (lp->ptid) == pid_was_stopped)
+    {
+      int err;
+
+      errno = 0;
+      err = kill_lwp (GET_LWP (lp->ptid), SIGSTOP);
+      if (debug_linux_nat)
+	{
+	  fprintf_unfiltered (gdb_stdlog,
+			      "SC:  lwp kill %d %s\n",
+			      err,
+			      errno ? safe_strerror (errno) : "ERRNO-OK");
+	}
+    }
 
   return 0;
 }